The overall objectives of this research project are to: study the population dynamics, seasonal abundance, spatial and temporal distribution, and species composition of house-dust mites; assess mite abundance in homes of asthmatic and nonasthmatic humans and to correlate this with incidence of asthma; determine air-borne mites and parts in rooms during bed-making and vacuuming, develop semi-chemically defined nonallergenic diet(s) for mite culturing: develop mass separation techniques from laboratory cultures: study inter- and intraspecific competition; elucidate the relationship between house-dust control measures and abundance of mites; and study the efficacy of physico-chemical control measures for these mites. BIBLIOGRAPHIC REFERENCE: Lang, James D. and Mir S. Mulla. l977. Factors influencing the abundance of house-dust mites Dermatophagoides Spp. in southern California. Environ. Entomol., (in press).